Software pirates and hackers intent on foiling Windows Vista activation have succeeded to some extent, a senior manager at Microsoft stated in a blog post earlier this week.

There are two methods that seem to work, and the software giant is monitoring both to see if they pose any substantial threat to the company's business model. One technique requires a special editor for the the software that acts as the interface between the PC hardware and the operating system, known as the Basic Input/Output System (BIOS). By editing a special value that PC manufacturers use to pass the product activation test, a hacker can run Windows Vista, said Alex Kochis, senior product manager for Microsoft, stated on the Windows Genuine Advantage blog.

The technique could easily result in an inoperable PC if done wrong, he said.

"It's worth noting we also prioritize our responses, because not every attempt deserves the same level of response," he wrote. "Our goal isn't to stop every 'mad scientist' that's on a mission to hack Windows."

A second hack uses emulation to attempt to defeat product activation and is easier to pull off, but also easier to detect, he said.

Product activation, an anti-copying technique designed to foil digital pirates, has come under criticism in the past as adding an extra step for legitimate users while not acting as much of a deterrent against theft. The latest end-user license agreement adopted for Windows Vista and part of activation has come under criticism as well.

Microsoft's Kochis said the company will consider the impact on customers of any change to the anti-piracy software.